Pergunta de entrevista da empresa FlightAware

all the questions were string manipulation, 1) Reverse a string, 2) Remove non alpha numerics from a string, 3) if a list of numbers has a repeat return true if not return false, 4) given a file of rows, parse and count the number of occurances of each value in a given row. Simple algorithmic problems really. Weird thing was that the interviewer was completely quiet, felt like coding in a room with a glass wall.